Instruments for telling time at night by reference to stars have been used for at least two centuries. Instruments of this type are disclosed in the patents to Thompson, U.S. Pat. No. 2,582,179 and to Fleming, U.S. Pat. No. 3,073,032. In general these devices are relatively complicated, include accurately-made and precisely-adjusted parts, and require outside equipment such as a chronometer or a light source for proper setting or operation. Similarly, the instrument in the patent to Wagoner, U.S. Pat. No. 4,103,429, while simpler in design than the devices of the other two patents, still requires a stand or base to rest on, is cumbersome, and cannot be easily carried from place to place. Further, this device is limited to the observation of one star only, namely, Dubhe Ursa Major and this condition limits the amount of time that the instrument can be used for observation since, at many latitudes, Dubhe Ursa Major is observable in the month of July only from dusk to midnight, and in the month of October only from 2 a.m. to dawn. Also, none of the three above-mentioned instruments can be used to determine at night the longitude of an occupied position.
An object of the present invention is to provide a simple, very lightweight, completely portable nocturnal time piece that can be used as a hand-held device to accurately tell standard time on any clear night throughout the entire year with no outside equipment and with a limited amount of instructions.